Dyke Swarms Florianópolis: Petrologic and Structural Aspects Related to Rifting Supercontinent Gondwana and Formation South Atlantic in the Santa Catarina of Island, Brazil

Supercontinent is registered on the South American shelf in continental flood basalts, mafic dyke swarms, basins rift and, to a lesser extent, by intrusions alkaline. Among those events, stands out in the south of Brazil intrusions of Dyke Swarms Florianópolis in the Santa Catarina of Island (SCI). The SCI (Fig.1), in namesake state, is located between parallels 27°10’ and 27°50’ south latitude and between meridians 48°25’ and 48°35’ west longitude, it presents elongated kilometers of extension toward northeast, as a result to structural configuration of rock masses, today interconnected by sedimentation areas Quaternary. This rock masses are composed predominantly by Alkaline Granite course equigranular (Island Granite) as also by volcanic and plutonic rocks predominantly by saturated rocks in silica that composes the Volcanic and Plutonic Suite Cambirela (Zanini et al, 1997). The Island Granite is intrusive in Gneisses ad Migmatites of the Águas Mornas Complex, which occurs on continental area adjacent to the Island and, in the northeastern portion of Island. The’re truncated by mafic dyke swarms that compose Florianópolis Dyke Swarms, Cretace Age (Raposo et al, 1998). On Quaternary deposits of coastal plain occurs among heave minerals, significant concentration of Fe and Ti Óxides (magnetite-ilmenite) from this dykes (Tomazzoli et al 2007). The Florianópolis Dyke Swarms (FDS) is compose, predominantly, by diabase dykes, basaltic andesite and, subordinately, andesite, with thicknesses ranging from centimetric/metric to greater than 200 meters, and can be prolong, in some cases, continuously for several kilometers (Fig.2). The majority is oriented toward N10°-30°E e, a lesser extent, toward N20°-30°W and N-S. There is, in certain places, intersection relation between dykes, normally, with thinner dikes toward NW and E-W truncated older dykes that following the general direction. The Florianópolis Dyke Swarms integrate the Parana Magmatic Province (PMP) (Fig.3), correspondent Etendeka Magmatic Province to African Plate. Besides of FDS, the PMP comprises by extensive acidic and basic flood by Ponta Grossa Dyke Swarms, Serra do Mar dyke Swarms and rift basins basalts (Pelotas, Santos, Campos e Espírito Santo). The FDS is compose predominantly by dike basalts and andesite basaltic. Also, occur intermediate dykes and dacite dykes. Petrographically basic bodies show different textures, from aphanitic to pórfiras (rare), with the predominance of subofítica and thin intergranular plot. Its essential minerals are plagioclase, augite, pigeonite, iron-titanium oxides, with apatite as mineral more abundant accessory epidote and / sericite as secondary minerals. The flood basaltic of PMP were divided into six different types of magmas, based primarily on the Edison R. Tomazzoli and Jean de B. Veronez, 2016. Dyke Swarms Florianópolis: Petrologic and Structural Aspects Related to Rifting Supercontinent Gondwana and Formation South Atlantic in the Santa Catarina of Island, Brazil. Acta Geologica Sinica (English Edition), 90(supp. 1): 94-96.